oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2020 ( 1 )

2019 ( 192 )

2018 ( 247 )

2017 ( 249 )

Custom range...

Search Results: 1 - 10 of 146524 matches for " Axel Bürkle "
All listed articles are free for downloading (OA Articles)
Page 1 /146524
Display every page Item
A Framework for Agent-based Human Interaction Support
Axel Bürkle,Wilmuth Müller,Uwe Pfirrmann,Manfred Schenk
Journal of Systemics, Cybernetics and Informatics , 2008,
Abstract: In this paper we describe an agent-based infrastructure for multimodal perceptual systems which aims at developing and realizing computer services that are delivered to humans in an implicit and unobtrusive way. The framework presented here supports the implementation of human-centric context-aware applications providing non-obtrusive assistance to participants in events such as meetings, lectures, conferences and presentations taking place in indoor "smart spaces". We emphasize on the design and implementation of an agent-based framework that supports "pluggable" service logic in the sense that the service developer can concentrate on coding the service logic independently of the underlying middleware. Furthermore, we give an example of the architecture's ability to support the cooperation of multiple services in a meeting scenario using an intelligent connector service and a semantic web oriented travel service.
Nützliche Illusionen
Stefanie Bürkle
s u b u r b a n : zeitschrift für kritische stadtforschung , 2013,
Abstract: In der Zweckarchitektur der Wasserversuchsanstalt in Berlin werden Schiffsmodelle auf ihre Seetauglichkeit hin überprüft; der stadtverw hnte Parisien erlernte in der Badeanstalt Piscine Pontoise das Schwimmen in einer Passage. Beide Motive der Arbeit Minimeere“ zeigen einen Mikrokosmos, der erschaffen worden ist, um natürliche Bedingungen zu simulieren, für wissenschaftliche Zwecke und das zweckfreie Amüsement. Stefanie Bürkles Fotoarbeiten aus der Serie Nützliche Illusionen sind Stereosichten auf eine Welt der Stadt- und Raumstrukturen, in denen links und rechts unterschiedliche Motive aufeinandertreffen. Links t uschen uns bei der Arbeit Dimensionen“ die Nutzbauten am Pariser Flughafen mit den Proportionen der europ ischen Stadt Leben vor, rechts sehen wir zwar den Markusplatz, doch nicht den in Venedig, sondern ma stabsgetreu errichtet in einem Themenpark in Shenzhen. über die Bildmitte hinweg setzen sich Perspektivlinien auf der jeweils anderen Bildh lfte fort. So baut der oszillierende Blick, der zwischen den Motiven springt und Strukturen abzugleichen sucht, um sie zur Kongruenz zu bringen, ein neues Gefüge, in dem Gegenstands- und Bildstruktur sich treffen und verdichten. Nach Kürzung aller augenscheinlichen Gemeinsamkeiten liegt die eigentliche Essenz der Fotografien blo . Eine auf das Wesentliche reduzierte Gleichung betrachten Mathematiker als sch n. Die Sch nheit der Gleichungen bei den Nützlichen Illusionen erscheint essentiell in ihren Widersprüchen. Sie bilden einen neuen, assoziativen Raum jenseits der Abbildungen – einen Raum der Illusionen.
Pleiotropic Cellular Functions of PARP1 in Longevity and Aging: Genome Maintenance Meets Inflammation
Aswin Mangerich,Alexander Bürkle
Oxidative Medicine and Cellular Longevity , 2012, DOI: 10.1155/2012/321653
Abstract: Aging is a multifactorial process that depends on diverse molecular and cellular mechanisms, such as genome maintenance and inflammation. The nuclear enzyme poly(ADP-ribose) polymerase 1 (PARP1), which catalyzes the synthesis of the biopolymer poly(ADP-ribose), exhibits an essential role in both processes. On the one hand, PARP1 serves as a genomic caretaker as it participates in chromatin remodelling, DNA repair, telomere maintenance, resolution of replicative stress, and cell cycle control. On the other hand, PARP1 acts as a mediator of inflammation due to its function as a regulator of NF-κB and other transcription factors and its potential to induce cell death. Consequently, PARP1 represents an interesting player in several aging mechanisms and is discussed as a longevity assurance factor on the one hand and an aging-promoting factor on the other hand. Here, we review the molecular mechanisms underlying the various roles of PARP1 in longevity and aging with special emphasis on cellular studies and we briefly discuss the results in the context of in vivo studies in mice and humans.
Pleiotropic Cellular Functions of PARP1 in Longevity and Aging: Genome Maintenance Meets Inflammation
Aswin Mangerich,Alexander Bürkle
Oxidative Medicine and Cellular Longevity , 2012, DOI: 10.1155/2012/321653
Abstract: Aging is a multifactorial process that depends on diverse molecular and cellular mechanisms, such as genome maintenance and inflammation. The nuclear enzyme poly(ADP-ribose) polymerase 1 (PARP1), which catalyzes the synthesis of the biopolymer poly(ADP-ribose), exhibits an essential role in both processes. On the one hand, PARP1 serves as a genomic caretaker as it participates in chromatin remodelling, DNA repair, telomere maintenance, resolution of replicative stress, and cell cycle control. On the other hand, PARP1 acts as a mediator of inflammation due to its function as a regulator of NF-κB and other transcription factors and its potential to induce cell death. Consequently, PARP1 represents an interesting player in several aging mechanisms and is discussed as a longevity assurance factor on the one hand and an aging-promoting factor on the other hand. Here, we review the molecular mechanisms underlying the various roles of PARP1 in longevity and aging with special emphasis on cellular studies and we briefly discuss the results in the context of in vivo studies in mice and humans. 1. Genomic Stability, Inflammation, and Aging Aging has been defined as a progressive postmaturational decline in physiological capacity, accompanied by an increased susceptibility to disease and an increased mortality risk. Mechanisms to maintain genomic stability are thought to counteract the aging process, whereas inflammation is considered a driving force of human aging [1]. A large body of evidence supports the theory that genomic instability acts as a causative factor in the aging process, which is evident from the fact that most mouse models of premature aging as well as human progeria syndromes are related to defects in mechanisms of genomic maintenance [2]. This may be attributed to the fact that DNA serves as a blueprint of all cellular RNAs and proteins. Any acquired change in its sequence, which may arise from molecular damage, is permanent and thus may have irreversible consequences. For this reason nature invested in a sophisticated network of various mechanisms (i) to maintain genome integrity, such as DNA repair and cell cycle control, and (ii) to withdraw heavily damaged cells from the body, such as apoptosis and cellular senescence. However, even if these mechanisms may be very efficient they cannot cope with all the insults induced in the genome, leading to a gradual accumulation of DNA damage and mutations, thus contributing to organismic aging [2]. On the other hand, a direct relationship exists between physiological aging and increasing incidence of
First-principles calculation of the thermoelectric figure of merit for [2,2]paracyclophane-based single-molecule junctions
Marius Bürkle,Thomas J. Hellmuth,Fabian Pauly,Yoshihiro Asai
Physics , 2015, DOI: 10.1103/PhysRevB.91.165419
Abstract: Here we present a theoretical study of the thermoelectric transport through {[}2,2{]}para\-cyclo\-phane-based single-molecule junctions. Combining electronic and vibrational structures, obtained from density functional theory (DFT), with nonequilibrium Green's function techniques, allows us to treat both electronic and phononic transport properties at a first-principles level. For the electronic part, we include an approximate self-energy correction, based on the DFT+$\Sigma$ approach. This enables us to make a reliable prediction of all linear response transport coefficients entering the thermoelectric figure of merit $ZT$. Paracyclophane derivatives offer a great flexibility in tuning their chemical properties by attaching different functional groups. We show that, for the specific molecule, the functional groups mainly influence the thermopower, allowing to tune its sign and absolute value. We predict that the functionalization of the bare paracyclophane leads to a largely enhanced electronic contribution $Z_{\mathrm{el}}T$ to the figure of merit. Nevertheless, the high phononic contribution to the thermal conductance strongly suppresses $ZT$. Our work demonstrates the importance to include the phonon thermal conductance for any realistic estimate of the $ZT$ for off-resonant molecular transport junctions. In addition, it shows the possibility of a chemical tuning of the thermoelectric properties for a series of available molecules, leading to equally performing hole- and electron-conducting junctions based on the same molecular framework.
DNA Damage in Nijmegen Breakage Syndrome Cells Leads to PARP Hyperactivation and Increased Oxidative Stress
Harald Krenzlin,Ilja Demuth,Bastian Salewsky,Petra Wessendorf,Kathrin Weidele,Alexander Bürkle,Martin Digweed
PLOS Genetics , 2012, DOI: 10.1371/journal.pgen.1002557
Abstract: Nijmegen Breakage Syndrome (NBS), an autosomal recessive genetic instability syndrome, is caused by hypomorphic mutation of the NBN gene, which codes for the protein nibrin. Nibrin is an integral member of the MRE11/RAD50/NBN (MRN) complex essential for processing DNA double-strand breaks. Cardinal features of NBS are immunodeficiency and an extremely high incidence of hematological malignancies. Recent studies in conditional null mutant mice have indicated disturbances in redox homeostasis due to impaired DSB processing. Clearly this could contribute to DNA damage, chromosomal instability, and cancer occurrence. Here we show, in the complete absence of nibrin in null mutant mouse cells, high levels of reactive oxygen species several hours after exposure to a mutagen. We show further that NBS patient cells, which unlike mouse null mutant cells have a truncated nibrin protein, also have high levels of reactive oxygen after DNA damage and that this increased oxidative stress is caused by depletion of NAD+ due to hyperactivation of the strand-break sensor, Poly(ADP-ribose) polymerase. Both hyperactivation of Poly(ADP-ribose) polymerase and increased ROS levels were reversed by use of a specific Poly(ADP-ribose) polymerase inhibitor. The extremely high incidence of malignancy among NBS patients is the result of the combination of a primary DSB repair deficiency with secondary oxidative DNA damage.
Chromatin Composition Is Changed by Poly(ADP-ribosyl)ation during Chromatin Immunoprecipitation
Sascha Beneke, Kirstin Meyer, Anja Holtz, Katharina Hüttner, Alexander Bürkle
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0032914
Abstract: Chromatin-immunoprecipitation (ChIP) employs generally a mild formaldehyde cross-linking step, which is followed by isolation of specific protein-DNA complexes and subsequent PCR testing, to analyze DNA-protein interactions. Poly(ADP-ribosyl)ation, a posttranslational modification involved in diverse cellular functions like repair, replication, transcription, and cell death regulation, is most prominent after DNA damage. Poly(ADP-ribose)polymerase-1 is activated upon binding to DNA strand-breaks and coordinates repair by recruitment or displacement of proteins. Several proteins involved in different nuclear pathways are directly modified or contain poly(ADP-ribose)-interaction motifs. Thus, poly(ADP-ribose) regulates chromatin composition. In immunofluorescence experiments, we noticed artificial polymer-formation after formaldehyde-fixation of undamaged cells. Therefore, we analyzed if the formaldehyde applied during ChIP also induces poly(ADP-ribosyl)ation and its impact on chromatin composition. We observed massive polymer-formation in three different ChIP-protocols tested independent on the cell line. This was due to induction of DNA damage signaling as monitored by γH2AX formation. To abrogate poly(ADP-ribose) synthesis, we inhibited this enzymatic reaction either pharmacologically or by increased formaldehyde concentration. Both approaches changed ChIP-efficiency. Additionally, we detected specific differences in promoter-occupancy of tested transcription factors as well as the in the presence of histone H1 at the respective sites. In summary, we show here that standard ChIP is flawed by artificial formation of poly(ADP-ribose) and suppression of this enzymatic activity improves ChIP-efficiency in general. Also, we detected specific changes in promoter-occupancy dependent on poly(ADP-ribose). By preventing polymer synthesis with the proposed modifications in standard ChIP protocols it is now possible to analyze the natural chromatin-composition.
Efeito da presen?a da folha no enraizamento de estacas semilenhosas de porta-enxertos de videira
Bordin, Ivan;Hidalgo, Paulo Cesar;Bürkle, Rodrigo;Roberto, Sérgio Ruffo;
Ciência Rural , 2005, DOI: 10.1590/S0103-84782005000100035
Abstract: the objective of this experiment was to study the rooting of semihardwood cuttings of the grapevine rootstocks iac 766 and iac 572, in mist chamber condition. for each rootstock, three types of cuttings were evaluated: with leaf, with half leaf, and without leaf. a randomized design was used as experimental model in a 2-factor arrangement (2 rootstocks genotypes and 3 types of cuttings), with five replications and 10 cuttings per plot. the results were evaluated by variance ana byssi and tukey test with 5% of probability. the rootstock iac 572 showed better rooting than iac 766. the leaf presence in semihardwood cuttings of grapevine was essential for adventicious root formation.
épocas de indu??o floral e soma térmica do período do florescimento à colheita de abacaxi 'Smooth Cayenne'
Carvalho, Sergio Luiz Colucci de;Neves, Carmen Silvia Vieira Janeiro;Bürkle, Rodrigo;Marur, Celso Jamil;
Revista Brasileira de Fruticultura , 2005, DOI: 10.1590/S0100-29452005000300022
Abstract: the knowledge of climate effects is important in planning pineapple production. the aim of this research was to accomplish the thermal time requirements of 'smooth cayenne' pineapple from the floral induction to the harvest period for different periods of artificial floral induction at northern state of paraná and also its influence in yield and fruit quality. the treatments were floral induction with ethephon in april, may, june and july. the control had natural induction. the inflorescence arose at 115.5; 107.3; 77.3 and 48.3 days after the floral induction for the applications in april, may, june, and july, respectively. the period between inflorescence arisen and harvest was 163 days for april induction, which was higher than for the other treatments (144 - 151 days). the fruits from the april treatment were smaller than the fruits from july. period of floral induction had no effect on titratable acidity, total soluble solids and ratio of the fruits. the thermal time requirement from the flowering to the harvest period was 1,090 degree-days, with no statistical difference among treatments.
An electronic health record to support patients and institutions of the health care system
ückert, Frank,Müller, Marcel Lucas,Bürkle, Thomas,Prokosch, Hans-Ulrich
GMS German Medical Science , 2004,
Abstract: The department of Medical Informatics of the University Hospital Münster and the Gesakon GmbH (an university offspring) initiated the cooperative development of an electronic health record (EHR) called "akteonline.de" in 2000. From 2001 onwards several clinics of the university hospital have already offered this EHR (within pilot projects) as an additional service to selected subsets of their patients. Based on the experiences of those pilot projects the system architecture and the basic data model underwent several evolutionary enhancements, e.g. implementations of electronic interfaces to other clinical systems (considering for example data interchange methods like the Clinical Document Architecture - standardized within the HL7 group - and also interfacing architectures of German GP systems, such as VCS and D2D). "akteonline.de" in its current structure supports patients as well as health care professionals and aims at providing a collaborative health information system which perfectly supports the clinical workflow even across institutional boundaries and including the patient himself. Since such an EHR needs to strictly fulfill high data security and data protection requirements, a complex authorization and access control component has been included. Furthermore the EHR data are encrypted within the database itself and during their transfer across the internet.
Page 1 /146524
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.